Shear reinforcement design on detailing provisions for column

 

Minimal shear reinforcement according to detailing provisions for beam is calculated according to formula

A_swm,min = max(A_swc,ϕ,min; A_swc,long,min)

where

Aswc,ϕ,min	minimal area of shear reinforcement from minimal bar diameter 9.5.3(1)
Aswc,long,min	minimal area of shear reinforcement from maximum longitudinal spacing 9.5.3(3)

Minimal area of shear reinforcement from minimal bar diameter 9.5.3(1)

Based on minimal bar diameter requirement which is defined in clause 9.5.3(1). It can be transformed to formula

ϕ_t,min,col = max(d_sc,min; xd_sc ∙ ϕ_l)

where

dsc,min	Minimal diameter of transverse reinforcement according to clause 9.5.3(1)
xdsc	Multiplication of the maximum diameter of the longitudinal bars
ϕl	Maximal diameter of the longitudinal bars

Final minimal area is calculated by

A_swc,ϕ,min = π ∙ ϕ_t,min,col² / 4 ∙ n_s

where

ϕt,min,col	Minimal diameter of transverse reinforcement according to clause 9.5.3(1)
ns	Number of cuts in one shear link

Minimal area of shear reinforcement from maximum longitudinal spacing 9.5.3(3)

Based on minimal allowed longitudinal spacing of transversal reinforcement which is defined in clause 9.5.3(3). It can be transformed to formula

s_cl,tmax = min(Coeff_cl,max,A ∙ ϕ_l; b_min; Coeff_cl,max,B)

where

Coeffcl,max,A	First coefficient for maximum allowed longitudinal spacing, can be changed in National annex setting. Default value 20
Coeffcl,max,B	Second coefficient for maximum allowed longitudinal spacing, can be changed in National annex setting. Default value 0,4 m
bmin	Lesser dimension of the column cross-section
ϕl	Maximal diameter of the longitudinal bars

Final minimal area is calculated by

A_swc,long,min = 1 / s_scl,tmax ∙ π ∙ ϕ² / 4 ∙ n_s

where

sscl,tmax	Maximum longitudinal spacing of transversal reinforcement according to clause 9.5.3(3)
ϕ	Diameter of shear reinforcement
ns	Number of cuts in one shear link

The values of coefficients or calculation procedures used in all detailing provisions can be modified by National annexes, for details see "National annexes theoretical background".